From 9c6ac0436356132da97c4bbb7f6c90b062438176 Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Mon, 2 Nov 2020 17:18:53 +0100 Subject: [PATCH] virtiofsd: Check FUSE_SUBMOUNTS FUSE_SUBMOUNTS is a pure indicator by the kernel to signal that it supports submounts. It does not check its state in the init reply, so there is nothing for fuse_lowlevel.c to do but to check its existence and copy it into fuse_conn_info.capable. Signed-off-by: Max Reitz Reviewed-by: Stefan Hajnoczi Message-Id: <20201102161859.156603-2-mreitz@redhat.com> Signed-off-by: Dr. David Alan Gilbert --- tools/virtiofsd/fuse_common.h | 7 +++++++ tools/virtiofsd/fuse_lowlevel.c | 3 +++ 2 files changed, 10 insertions(+) diff --git a/tools/virtiofsd/fuse_common.h b/tools/virtiofsd/fuse_common.h index 686c42c0a5..5aee5193eb 100644 --- a/tools/virtiofsd/fuse_common.h +++ b/tools/virtiofsd/fuse_common.h @@ -352,6 +352,13 @@ struct fuse_file_info { */ #define FUSE_CAP_NO_OPENDIR_SUPPORT (1 << 24) +/** + * Indicates that the kernel supports the FUSE_ATTR_SUBMOUNT flag. + * + * Setting (or unsetting) this flag in the `want` field has *no effect*. + */ +#define FUSE_CAP_SUBMOUNTS (1 << 27) + /** * Ioctl flags * diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c index 4d1ba2925d..370222339b 100644 --- a/tools/virtiofsd/fuse_lowlevel.c +++ b/tools/virtiofsd/fuse_lowlevel.c @@ -1988,6 +1988,9 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid, bufsize = max_bufsize; } } + if (arg->flags & FUSE_SUBMOUNTS) { + se->conn.capable |= FUSE_CAP_SUBMOUNTS; + } #ifdef HAVE_SPLICE #ifdef HAVE_VMSPLICE se->conn.capable |= FUSE_CAP_SPLICE_WRITE | FUSE_CAP_SPLICE_MOVE;